Driving circuit with impedence calibration

Abstract

A driving circuit includes at least a driving unit. The driving circuit includes a first bias component, a second bias component, and four metal-oxide-semiconductor (MOS) transistors. The first bias component has a first node coupled to a first reference voltage and a second node for outputting a first bias current. The second bias component has a first node for draining a second bias current and a second node coupled to a second reference voltage different from the first reference voltage. Each of the MOS transistors has a control node for receiving one of input signal pairs, a node coupled to one of the bias components and another node coupled to one of the output ports of the driving circuit. The four MOS transistors are of a same conductive type.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a driver, and more particularly, to a low power, high speed driving circuit with auto-calibration functionality.[0003]2. Description of the Prior Art[0004]As the resolution of image sensors or display increases, the data rate of becomes very high. As a result, a requirement for a high speed driver with superior performance grows. Among all kinds of high speed drivers, a low voltage differential signal (LVDS) technique is frequently utilized due to a lower electromagnetic interference (EMI), a lower power consumption and a better signal integrity than those of a conventional CMOS full swing driver. Please refer to FIG. 1, which is a diagram of a conventional LVDS driver for driving a pair of loads R1 and R2. The conventional LVDS driver 100 is composed of two PMOS transistors M1, M2, two NMOS transistors M3, M4, and two constant current sources I1 and I2 connected to a reference supply vo...

AI Technical Summary

Benefits of technology

[0007]To solve the abovementioned problems, an exemplary embodiment of the present invention therefore provides a novel driving circuit (e.g., a novel LDVS driver) capable of achieving the same performance with less power consumption.

Problems solved by technology

In this case, a tail current source connecting reference ground is impossible to be applied.

The LDVS driver 300 shown in FIG. 3 can successively meet the requirements of the MIPI standard but still suffers from an over-large power consumption (8 mA for one single driver).

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